1. Field of the invention
The present embodiment relates to a radar device for a vehicle and a method for estimating the angle of a target using the same and, more particularly, to a radar device for a vehicle, which may determine a target as a single target or multiple targets according to a phase difference for each reception channel of a reflection signal and a relative phase difference for each reception channel calculated through an arrangement interval for each reception channel, and estimate the angle of the target so as to acquire the angle of the target using a small amount of calculations, and a method for estimating the angle of a target using the same.
2. Description of the Prior Art
A radar using a Frequency Modulation Continuous Wave (FMCW) Array Antenna scheme extracts the angle of a target using a phase difference of a signal received by a plurality of receiving antennas arranged in a predetermined direction.
A conventional beamforming scheme among various algorithms for estimating an angle using such a phase difference is generally used due to advantages of stability of algorithms and a small amount of calculations.
However, even a conventional beamforming scheme has a disadvantage of increasing the amount of calculation by multiplex matrix calculations during a process for acquiring a power spectrum when a Field of View (FoV) is widened or the accuracy of an angle is intended to be improved.
Also, since the angular resolution for a multiple target situation has been limited in an identical antenna environment, a high resolution algorithm having a large amount of calculations needs to be applied in order to improve a multiple target angular resolution.
However, a high resolution algorithm shows a big difference in relation to the amount of calculation, and thus causes a waste of calculation for a single target to which the same cannot be applied. Further, it is required to distinguish a single target situation from a multiple target situation in order to avoid such a waste, but the determination therebetween is ambiguous.    (Patent document 1) Republic of Korea Patent Application Publication No. 2014-0083708 (2014 Jul. 4) entitled “Rader device and phase variation compensation method applied thereto”.